In oxidative hair coloring, the problem arises that irritation of the scalp and damage to the keratinic fibers can occur as a result of the aggressive agents. In particular, the natural hydrophobicity of the keratinic fibers is reduced because the coloring agents resp. lightening agents must first make the hair capable of penetration in order to exert their effect. The water-repellent effect on the one hand, however, provides natural protection for the hair; on the other hand, parameters desired by the consumer, such as shine, softness, suppleness, and the “drape” of the hair, are closely linked to it.
In order to overcome the aforesaid disadvantages, so-called pretreatment agents that are intended to protect the hair from aggressive influences are on the market. These often make the hair heavy, however, or negatively affect the outcome of the lightening resp. coloring of the hair that takes place subsequently; in particular, the washing fastness of the color can be degraded by the pretreatment agent. Also known are numerous post-treatment agents with which an attempt is made to repair the hair damage caused in the context of the oxidative coloring treatment. All these methods, however, require a multi-step utilization method, and even application of a further hair treatment agent either before or after coloring. This is often perceived by the consumer as burdensome, since the oxidative coloring treatment itself, with multiple working steps and a contact time of up to 60 minutes, is already very laborious.